如何从 SwiftUI 中的图库中选择图像
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【中文标题】如何从 SwiftUI 中的图库中选择图像【英文标题】：How to pick image from gallery in SwiftUI 【发布时间】：2019-07-19 10:17:23 【问题描述】：我尝试制作一个符合 UIViewRepresentable 并实现 makeUIView 和 updateUIView 的 SwiftUI 类。 但无法完成。这是代码：
代码：
struct ImagePicker : UIViewRepresentable
@Binding var image: UIImage
class Coordinator: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate
@Binding var image: UIImage
init(image: Binding<UIImage>)
$image = image
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any])
if let possibleImage = info[.editedImage] as? UIImage
image = possibleImage
else if let possibleImage = info[.originalImage] as? UIImage
image = possibleImage
else
func makeCoordinator() -> Coordinator
return Coordinator(image: $image)
func makeUIView(context: UIViewRepresentableContext<ImagePicker>) -> UIImageView
let imageview = UIImageView()
let picker = UIImagePickerController()
picker.delegate = context.coordinator
return imageview
func updateUIView(_ uiView: UIImageView,
context: UIViewRepresentableContext<ImagePicker>)
uiView.image = image
我尝试使用 imagePicker 作为控件但无法使用。
【问题讨论】：
我有一个工作版本的UIImagePickerController。查看您的代码，您已经接近了。但。首先，“它不起作用”是什么意思。 （更多细节会有所帮助。）接下来，我的版本基于对这个问题的公认答案：***.com/questions/56515871/… 但最后 - 抱歉大喊大叫 - 我的版本，那个版本，我猜你的版本都坏了在三天前发布的 beta 4 中。你运行的是什么版本的？
感谢您的回复。你的答案对我有用。
【参考方案1】：
我在这里使用presentationMode 来检查它是否呈现的视图？
通过使用这个你可以dismiss()UIImagePickerController。
SwiftUI 预览示例代码：
import SwiftUI
struct ContentView: View
@State var isShowPicker: Bool = false
@State var image: Image? = Image("placeholder")
var body: some View
NavigationView
ZStack
VStack
image?
.resizable()
.scaledToFit()
.frame(height: 320)
Button(action:
withAnimation
self.isShowPicker.toggle()
)
Image(systemName: "photo")
.font(.headline)
Text("IMPORT").font(.headline)
.foregroundColor(.black)
Spacer()
.sheet(isPresented: $isShowPicker)
ImagePicker(image: self.$image)
.navigationBarTitle("Pick Image")
struct ImagePicker: UIViewControllerRepresentable
@Environment(\.presentationMode)
var presentationMode
@Binding var image: Image?
class Coordinator: NSObject, UINavigationControllerDelegate, UIImagePickerControllerDelegate
@Binding var presentationMode: PresentationMode
@Binding var image: Image?
init(presentationMode: Binding<PresentationMode>, image: Binding<Image?>)
_presentationMode = presentationMode
_image = image
func imagePickerController(_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any])
let uiImage = info[UIImagePickerController.InfoKey.originalImage] as! UIImage
image = Image(uiImage: uiImage)
presentationMode.dismiss()
func imagePickerControllerDidCancel(_ picker: UIImagePickerController)
presentationMode.dismiss()
func makeCoordinator() -> Coordinator
return Coordinator(presentationMode: presentationMode, image: $image)
func makeUIViewController(context: UIViewControllerRepresentableContext<ImagePicker>) -> UIImagePickerController
let picker = UIImagePickerController()
picker.delegate = context.coordinator
return picker
func updateUIViewController(_ uiViewController: UIImagePickerController,
context: UIViewControllerRepresentableContext<ImagePicker>)
struct ContentView_Previews: PreviewProvider
static var previews: some View
NavigationView
ContentView()
【讨论】：
用户选择图片后，父类中的图片变量不填充。【参考方案2】：请试试这个
代码：
import SwiftUI
struct OpenGallary: UIViewControllerRepresentable
let isShown: Binding<Bool>
let image: Binding<Image?>
class Coordinator: NSObject, UINavigationControllerDelegate, UIImagePickerControllerDelegate
let isShown: Binding<Bool>
let image: Binding<Image?>
init(isShown: Binding<Bool>, image: Binding<Image?>)
self.isShown = isShown
self.image = image
func imagePickerController(_ picker: UIImagePickerController,
didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any])
let uiImage = info[UIImagePickerController.InfoKey.originalImage] as! UIImage
self.image.wrappedValue = Image(uiImage: uiImage)
self.isShown.wrappedValue = false
func imagePickerControllerDidCancel(_ picker: UIImagePickerController)
isShown.wrappedValue = false
func makeCoordinator() -> Coordinator
return Coordinator(isShown: isShown, image: image)
func makeUIViewController(context: UIViewControllerRepresentableContext<OpenGallary>) -> UIImagePickerController
let picker = UIImagePickerController()
picker.delegate = context.coordinator
return picker
func updateUIViewController(_ uiViewController: UIImagePickerController,
context: UIViewControllerRepresentableContext<OpenGallary>)
选择器显示在视图的正上方，没有过渡 所选图像出现时没有任何类型的动画，并替换了显示图像选择器按钮
之后创建显示视图，您可以在其中调用显示此 imagePicker
struct ContentView: View
@State var showImagePicker: Bool = false
@State var image: Image?
var body: some View
ZStack
VStack
Button(action:
withAnimation
self.showImagePicker.toggle()
)
Text("Show image picker")
image?.resizable().frame(width: 100, height: 100)
if (showImagePicker)
OpenGallary(isShown: $showImagePicker, image: $image)
【讨论】：
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